The murine cot proto-oncogene: genome structure and tissue-specific expression.

We cloned and analyzed the murine cot proto-oncogene and examined its tissue-specific expression in fetal, newborn and adult mice. Genomic cot DNA consists of eight exons, spanning more than 25 kb, and all intron-exon borders are well conserved as compared to the human homolog. Analysis of the full-length cot cDNA revealed that it contained an open reading frame of 1,401 nucleotides, like human cot proto-oncogene. The sequence identity between murine and human cot gene is 84.4% at the nucleotide level and 93.9% at the deduced amino acid level. On northern blot analysis of poly (A)+ RNA, the cot message was detected at 2.9 kb in size. Expression of the cot gene was observed in many tissues from fetal to adult mice, though the level of expression was low in all tissues examined.